Pre‐transplant immune cell function assay as a predictor of early cardiac allograft rejection

• Published in: Clinical transplantation Vol. 36; no. 7; pp. e14745 - n/a
• Main Authors: Maidman, Samuel D., Gidea, Claudia, Reyentovich, Alex, Rao, Shaline, Saraon, Tajinderpal, Kadosh, Bernard S., Narula, Navneet, Carillo, Julius, Smith, Deane, Moazami, Nader, Katz, Stuart, Goldberg, Randal I.
• Format: Journal Article
• Language: English
• Published: Denmark 01.07.2022
• Subjects: ImmuKnow; rejection; transplant; transplant; ImmuKnow; rejection
• ISSN: 0902-0063; 1399-0012
• DOI: 10.1111/ctr.14745

Introduction ImmuKnow, an immune cell function assay that quantifies overall immune system activity can assist in post‐transplant immunosuppression adjustment. However, the utility of pre‐transplant ImmuKnow results representing a patient's baseline immune system activity is unknown. This study sought to assess if pre‐transplant ImmuKnow results are predictive of rejection at the time of first biopsy in our cardiac transplant population. Methods This is a single center, retrospective observational study of consecutive patients from January 1, 2018 to October 1, 2020 who underwent orthotopic cardiac transplantation at NYU Langone Health. Patients were excluded if a pre‐transplant ImmuKnow assay was not performed. ImmuKnow results were categorized according to clinical interpretation ranges (low, moderate, and high activity), and patients were divided into two groups: a low activity group versus a combined moderate‐high activity group. Pre‐transplant clinical characteristics, induction immunosuppression use, early postoperative tacrolimus levels, and first endomyocardial biopsy results were collected for all patients. Rates of clinically significant early rejection (defined as rejection ≥ 1R/1B) were compared between pre‐transplant ImmuKnow groups. Results Of 110 patients who underwent cardiac transplant, 81 had pre‐transplant ImmuKnow results. The low ImmuKnow activity group was comprised of 15 patients, and 66 patients were in the combined moderate‐high group. Baseline characteristics were similar between groups. Early rejection occurred in 0 (0%) patients with low pre‐transplant ImmuKnow levels. Among the moderate‐ high pre‐transplant ImmuKnow group, 16 (24.2%) patients experienced early rejection (P = .033). The mean ImmuKnow level in the non‐rejection group was the 364.9 ng/ml of ATP compared to 499.3 ng/ml of ATP for those with rejection (P = .020). Conclusion Patients with low pre‐transplant ImmuKnow levels had lower risk of early rejection when compared with patients with moderate or high levels. Our study suggests a possible utility in performing pre‐transplant ImmuKnow to identify patients at‐risk for early rejection who may benefit from intensified upfront immunosuppression as well as to recognize those where slower calcineurin inhibitor initiation may be appropriate.